H 2 O 2 -responsive liposomal nanoprobe for photoacoustic inflammation imaging and tumor theranostics via in vivo chromogenic assay

Significance Hydrogen peroxide is closely associated with many important physiological and pathological events. Herein, we develop a liposomal nanoprobe for in vivo H 2 O 2 -responsive chromogenic assay, which is highly specific and sensitive to H 2 O 2 . Using such a nanoprobe, photoacoustic imaging of H 2 O 2 -related inflammation processes in mice induced by either LPS or bacteria is realized. Meanwhile, such a nanoprobe, by reacting with endogenous H 2 O 2 produced by tumor cells, allows sensitive photoacoustic imaging of early-stage small tumors and orthotopic brain glioma and even enables accurate differentiation of metastatic sentinel lymph nodes from nonmetastatic ones. Furthermore, owing to its H 2 O 2 -responsive near-infrared absorbance, selective photothermal ablation of tumors is also achieved, illustrating the promise of using this nanoproble for tumor theranostics with great specificity.